3 ;;;; This software is part of the SBCL system. See the README file for
6 ;;;; This software is derived from the CMU CL system, which was
7 ;;;; written at Carnegie Mellon University and released into the
8 ;;;; public domain. The software is in the public domain and is
9 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
10 ;;;; files for more information.
12 (in-package "SB!IMPL")
14 ;;;; exported printer control variables
16 ;;; FIXME: Many of these have nontrivial types, e.g. *PRINT-LEVEL*,
17 ;;; *PRINT-LENGTH*, and *PRINT-LINES* are (OR NULL UNSIGNED-BYTE).
19 (defvar *print-readably* nil
21 "If true, all objects will printed readably. If readable printing is
22 impossible, an error will be signalled. This overrides the value of
24 (defvar *print-escape* T
26 "Flag which indicates that slashification is on. See the manual")
27 (defvar *print-pretty* nil ; (set later when pretty-printer is initialized)
29 "Flag which indicates that pretty printing is to be used")
30 (defvar *print-base* 10.
32 "The output base for integers and rationals.")
33 (defvar *print-radix* nil
35 "This flag requests to verify base when printing rationals.")
36 (defvar *print-level* nil
38 "How many levels deep to print. Unlimited if null.")
39 (defvar *print-length* nil
41 "How many elements to print on each level. Unlimited if null.")
42 (defvar *print-circle* nil
44 "Whether to worry about circular list structures. See the manual.")
45 (defvar *print-case* :upcase
47 "What kind of case the printer should use by default")
48 (defvar *print-array* t
50 "Whether the array should print its guts out")
51 (defvar *print-gensym* t
53 "If true, symbols with no home package are printed with a #: prefix.
54 If false, no prefix is printed.")
55 (defvar *print-lines* nil
57 "The maximum number of lines to print. If NIL, unlimited.")
58 (defvar *print-right-margin* nil
60 "The position of the right margin in ems. If NIL, try to determine this
61 from the stream in use.")
62 (defvar *print-miser-width* nil
64 "If the remaining space between the current column and the right margin
65 is less than this, then print using ``miser-style'' output. Miser
66 style conditional newlines are turned on, and all indentations are
67 turned off. If NIL, never use miser mode.")
68 (defvar *print-pprint-dispatch* nil
70 "The pprint-dispatch-table that controls how to pretty print objects. See
71 COPY-PPRINT-DISPATH, PPRINT-DISPATCH, and SET-PPRINT-DISPATCH.")
73 (defmacro with-standard-io-syntax (&body body)
75 "Bind the reader and printer control variables to values that enable READ
76 to reliably read the results of PRINT. These values are:
77 *PACKAGE* the COMMON-LISP-USER package
87 *PRINT-MISER-WIDTH* NIL
91 *PRINT-RIGHT-MARGIN* NIL
93 *READ-DEFAULT-FLOAT-FORMAT* SINGLE-FLOAT
96 *READTABLE* the standard readtable."
97 `(%with-standard-io-syntax #'(lambda () ,@body)))
99 (defun %with-standard-io-syntax (function)
100 (let ((*package* (find-package "COMMON-LISP-USER"))
103 (*print-case* :upcase)
110 (*print-miser-width* nil)
114 (*print-right-margin* nil)
116 (*read-default-float-format* 'single-float)
118 (*read-suppress* nil)
119 ;; FIXME: It doesn't seem like a good idea to expose our
120 ;; disaster-recovery *STANDARD-READTABLE* here. What if some
121 ;; enterprising user corrupts the disaster-recovery readtable
122 ;; by doing destructive readtable operations within
123 ;; WITH-STANDARD-IO-SYNTAX? Perhaps we should do a
124 ;; COPY-READTABLE? The consing would be unfortunate, though.
125 (*readtable* *standard-readtable*))
128 ;;;; routines to print objects
130 (defun write (object &key
131 ((:stream stream) *standard-output*)
132 ((:escape *print-escape*) *print-escape*)
133 ((:radix *print-radix*) *print-radix*)
134 ((:base *print-base*) *print-base*)
135 ((:circle *print-circle*) *print-circle*)
136 ((:pretty *print-pretty*) *print-pretty*)
137 ((:level *print-level*) *print-level*)
138 ((:length *print-length*) *print-length*)
139 ((:case *print-case*) *print-case*)
140 ((:array *print-array*) *print-array*)
141 ((:gensym *print-gensym*) *print-gensym*)
142 ((:readably *print-readably*) *print-readably*)
143 ((:right-margin *print-right-margin*)
144 *print-right-margin*)
145 ((:miser-width *print-miser-width*)
147 ((:lines *print-lines*) *print-lines*)
148 ((:pprint-dispatch *print-pprint-dispatch*)
149 *print-pprint-dispatch*))
151 "Output OBJECT to the specified stream, defaulting to *STANDARD-OUTPUT*"
152 (output-object object (out-synonym-of stream))
155 (defun prin1 (object &optional stream)
157 "Output a mostly READable printed representation of OBJECT on the specified
159 (let ((*print-escape* T))
160 (output-object object (out-synonym-of stream)))
163 (defun princ (object &optional stream)
165 "Output an aesthetic but not necessarily READable printed representation
166 of OBJECT on the specified STREAM."
167 (let ((*print-escape* NIL)
168 (*print-readably* NIL))
169 (output-object object (out-synonym-of stream)))
172 (defun print (object &optional stream)
174 "Output a newline, the mostly READable printed representation of OBJECT, and
175 space to the specified STREAM."
176 (let ((stream (out-synonym-of stream)))
178 (prin1 object stream)
179 (write-char #\space stream)
182 (defun pprint (object &optional stream)
184 "Prettily output OBJECT preceded by a newline."
185 (let ((*print-pretty* t)
187 (stream (out-synonym-of stream)))
189 (output-object object stream))
192 (defun write-to-string
194 ((:escape *print-escape*) *print-escape*)
195 ((:radix *print-radix*) *print-radix*)
196 ((:base *print-base*) *print-base*)
197 ((:circle *print-circle*) *print-circle*)
198 ((:pretty *print-pretty*) *print-pretty*)
199 ((:level *print-level*) *print-level*)
200 ((:length *print-length*) *print-length*)
201 ((:case *print-case*) *print-case*)
202 ((:array *print-array*) *print-array*)
203 ((:gensym *print-gensym*) *print-gensym*)
204 ((:readably *print-readably*) *print-readably*)
205 ((:right-margin *print-right-margin*) *print-right-margin*)
206 ((:miser-width *print-miser-width*) *print-miser-width*)
207 ((:lines *print-lines*) *print-lines*)
208 ((:pprint-dispatch *print-pprint-dispatch*)
209 *print-pprint-dispatch*))
211 "Return the printed representation of OBJECT as a string."
212 (stringify-object object))
214 (defun prin1-to-string (object)
216 "Return the printed representation of OBJECT as a string with
218 (stringify-object object t))
220 (defun princ-to-string (object)
222 "Return the printed representation of OBJECT as a string with
224 (stringify-object object nil))
226 ;;; This produces the printed representation of an object as a string.
227 ;;; The few ...-TO-STRING functions above call this.
228 (defvar *string-output-streams* ())
229 (defun stringify-object (object &optional (*print-escape* *print-escape*))
230 (let ((stream (if *string-output-streams*
231 (pop *string-output-streams*)
232 (make-string-output-stream))))
233 (setup-printer-state)
234 (output-object object stream)
236 (get-output-stream-string stream)
237 (push stream *string-output-streams*))))
239 ;;;; support for the PRINT-UNREADABLE-OBJECT macro
241 ;;; guts of PRINT-UNREADABLE-OBJECT
242 (defun %print-unreadable-object (object stream type identity body)
243 (when *print-readably*
244 (error 'print-not-readable :object object))
245 (flet ((print-description ()
247 (write (type-of object) :stream stream :circle nil
248 :level nil :length nil)
249 (when (or body identity)
250 (write-char #\space stream)
251 (pprint-newline :fill stream)))
256 (write-char #\space stream)
257 (pprint-newline :fill stream))
258 (write-char #\{ stream)
259 (write (get-lisp-obj-address object) :stream stream
261 (write-char #\} stream))))
262 (cond ((print-pretty-on-stream-p stream)
263 ;; Since we're printing prettily on STREAM, format the
264 ;; object within a logical block. PPRINT-LOGICAL-BLOCK does
265 ;; not rebind the stream when it is already a pretty stream,
266 ;; so output from the body will go to the same stream.
267 (pprint-logical-block (stream nil :prefix "#<" :suffix ">")
268 (print-description)))
270 (write-string "#<" stream)
272 (write-char #\> stream))))
275 ;;;; circularity detection stuff
277 ;;; When *PRINT-CIRCLE* is T, this gets bound to a hash table that
278 ;;; (eventually) ends up with entries for every object printed. When
279 ;;; we are initially looking for circularities, we enter a T when we
280 ;;; find an object for the first time, and a 0 when we encounter an
281 ;;; object a second time around. When we are actually printing, the 0
282 ;;; entries get changed to the actual marker value when they are first
284 (defvar *circularity-hash-table* nil)
286 ;;; When NIL, we are just looking for circularities. After we have
287 ;;; found them all, this gets bound to 0. Then whenever we need a new
288 ;;; marker, it is incremented.
289 (defvar *circularity-counter* nil)
291 ;;; Check to see whether OBJECT is a circular reference, and return something
292 ;;; non-NIL if it is. If ASSIGN is T, then the number to use in the #n= and
293 ;;; #n# noise is assigned at this time. Note: CHECK-FOR-CIRCULARITY must
294 ;;; be called *EXACTLY* once with ASSIGN T, or the circularity detection noise
295 ;;; will get confused about when to use #n= and when to use #n#. If this
296 ;;; returns non-NIL when ASSIGN is T, then you must call HANDLE-CIRCULARITY
297 ;;; on it. If you are not using this inside a WITH-CIRCULARITY-DETECTION,
298 ;;; then you have to be prepared to handle a return value of :INITIATE which
299 ;;; means it needs to initiate the circularity detection noise. See the
300 ;;; source for info on how to do that.
301 (defun check-for-circularity (object &optional assign)
302 (cond ((null *print-circle*)
303 ;; Don't bother, nobody cares.
305 ((null *circularity-hash-table*)
307 ((null *circularity-counter*)
308 (ecase (gethash object *circularity-hash-table*)
311 (setf (gethash object *circularity-hash-table*) t)
312 ;; We need to keep looking.
316 (setf (gethash object *circularity-hash-table*) 0)
317 ;; It's a circular reference.
320 ;; It's a circular reference.
323 (let ((value (gethash object *circularity-hash-table*)))
326 ;; If NIL, we found an object that wasn't there the first time
327 ;; around. If T, exactly one occurance of this object appears.
328 ;; Either way, just print the thing without any special
329 ;; processing. Note: you might argue that finding a new object
330 ;; means that something is broken, but this can happen. If
331 ;; someone uses the ~@<...~:> format directive, it conses a
332 ;; new list each time though format (i.e. the &REST list), so
333 ;; we will have different cdrs.
337 (let ((value (incf *circularity-counter*)))
338 ;; First occurance of this object. Set the counter.
339 (setf (gethash object *circularity-hash-table*) value)
343 ;; Second or later occurance.
346 ;;; Handle the results of CHECK-FOR-CIRCULARITY. If this returns T then
347 ;;; you should go ahead and print the object. If it returns NIL, then
348 ;;; you should blow it off.
349 (defun handle-circularity (marker stream)
352 ;; Someone forgot to initiate circularity detection.
353 (let ((*print-circle* nil))
354 (error "trying to use CHECK-FOR-CIRCULARITY when ~
355 circularity checking isn't initiated")))
357 ;; It's a second (or later) reference to the object while we are
358 ;; just looking. So don't bother groveling it again.
361 (write-char #\# stream)
362 (let ((*print-base* 10) (*print-radix* nil))
363 (cond ((minusp marker)
364 (output-integer (- marker) stream)
365 (write-char #\# stream)
368 (output-integer marker stream)
369 (write-char #\= stream)
372 ;;;; OUTPUT-OBJECT -- the main entry point
374 (defvar *pretty-printer* nil
376 "The current pretty printer. Should be either a function that takes two
377 arguments (the object and the stream) or NIL to indicate that there is
378 no pretty printer installed.")
380 ;;; Output OBJECT to STREAM observing all printer control variables.
381 (defun output-object (object stream)
382 (labels ((print-it (stream)
385 (funcall *pretty-printer* object stream)
386 (let ((*print-pretty* nil))
387 (output-ugly-object object stream)))
388 (output-ugly-object object stream)))
390 (let ((marker (check-for-circularity object t)))
393 (let ((*circularity-hash-table*
394 (make-hash-table :test 'eq)))
395 (check-it (make-broadcast-stream))
396 (let ((*circularity-counter* 0))
401 (when (handle-circularity marker stream)
402 (print-it stream)))))))
403 (cond ((or (not *print-circle*)
406 (and (symbolp object) (symbol-package object) t))
407 ;; If it a number, character, or interned symbol, we do not
408 ;; want to check for circularity/sharing.
410 ((or *circularity-hash-table*
412 (typep object 'instance)
413 (typep object '(array t *)))
414 ;; If we have already started circularity detection, this
415 ;; object might be a sharded reference. If we have not,
416 ;; then if it is a cons, a instance, or an array of element
417 ;; type t it might contain a circular reference to itself
418 ;; or multiple shared references.
421 (print-it stream)))))
423 ;;; Output OBJECT to STREAM observing all printer control variables
424 ;;; except for *PRINT-PRETTY*. Note: if *PRINT-PRETTY* is non-NIL,
425 ;;; then the pretty printer will be used for any components of OBJECT,
426 ;;; just not for OBJECT itself.
427 (defun output-ugly-object (object stream)
429 ;; KLUDGE: The TYPECASE approach here is non-ANSI; the ANSI definition of
430 ;; PRINT-OBJECT says it provides printing and we're supposed to provide
431 ;; PRINT-OBJECT methods covering all classes. We deviate from this
432 ;; by using PRINT-OBJECT only when we print instance values. However,
433 ;; ANSI makes it hard to tell that we're deviating from this:
434 ;; (1) ANSI specifies that the user isn't supposed to call PRINT-OBJECT
436 ;; (2) ANSI (section 11.1.2.1.2) says it's undefined to define
437 ;; a method on an external symbol in the CL package which is
438 ;; applicable to arg lists containing only direct instances of
439 ;; standardized classes.
440 ;; Thus, in order for the user to detect our sleaziness, he has to do
441 ;; something relatively obscure like
442 ;; (1) actually use tools like FIND-METHOD to look for PRINT-OBJECT
444 ;; (2) define a PRINT-OBJECT method which is specialized on the stream
445 ;; value (e.g. a Gray stream object).
446 ;; As long as no one comes up with a non-obscure way of detecting this
447 ;; sleaziness, fixing this nonconformity will probably have a low
448 ;; priority. -- WHN 20000121
450 (output-integer object stream))
453 (output-symbol object stream)
454 (output-list object stream)))
456 (print-object object stream))
458 (unless (and (funcallable-instance-p object)
459 (printed-as-funcallable-standard-class object stream))
460 (output-function object stream)))
462 (output-symbol object stream))
466 (output-integer object stream))
468 (output-float object stream))
470 (output-ratio object stream))
472 (output-ratio object stream))
474 (output-complex object stream))))
476 (output-character object stream))
478 (output-vector object stream))
480 (output-array object stream))
482 (output-sap object stream))
484 (output-weak-pointer object stream))
486 (output-lra object stream))
488 (output-code-component object stream))
490 (output-fdefn object stream))
492 (output-random object stream))))
496 ;;; Values of *PRINT-CASE* and (READTABLE-CASE *READTABLE*) the last
497 ;;; time the printer was called.
498 (defvar *previous-case* nil)
499 (defvar *previous-readtable-case* nil)
501 ;;; This variable contains the current definition of one of three
502 ;;; symbol printers. SETUP-PRINTER-STATE sets this variable.
503 (defvar *internal-symbol-output-function* nil)
505 ;;; This function sets the internal global symbol
506 ;;; *INTERNAL-SYMBOL-OUTPUT-FUNCTION* to the right function depending
507 ;;; on the value of *PRINT-CASE*. See the manual for details. The
508 ;;; print buffer stream is also reset.
509 (defun setup-printer-state ()
510 (unless (and (eq *print-case* *previous-case*)
511 (eq (readtable-case *readtable*) *previous-readtable-case*))
512 (setq *previous-case* *print-case*)
513 (setq *previous-readtable-case* (readtable-case *readtable*))
514 (unless (member *print-case* '(:upcase :downcase :capitalize))
515 (setq *print-case* :upcase)
516 (error "invalid *PRINT-CASE* value: ~S" *previous-case*))
517 (unless (member *previous-readtable-case*
518 '(:upcase :downcase :invert :preserve))
519 (setf (readtable-case *readtable*) :upcase)
520 (error "invalid READTABLE-CASE value: ~S" *previous-readtable-case*))
522 (setq *internal-symbol-output-function*
523 (case *previous-readtable-case*
526 (:upcase #'output-preserve-symbol)
527 (:downcase #'output-lowercase-symbol)
528 (:capitalize #'output-capitalize-symbol)))
531 (:upcase #'output-uppercase-symbol)
532 (:downcase #'output-preserve-symbol)
533 (:capitalize #'output-capitalize-symbol)))
534 (:preserve #'output-preserve-symbol)
535 (:invert #'output-invert-symbol)))))
537 ;;; Output PNAME (a symbol-name or package-name) surrounded with |'s,
538 ;;; and with any embedded |'s or \'s escaped.
539 (defun output-quoted-symbol-name (pname stream)
540 (write-char #\| stream)
541 (dotimes (index (length pname))
542 (let ((char (schar pname index)))
543 (when (or (char= char #\\) (char= char #\|))
544 (write-char #\\ stream))
545 (write-char char stream)))
546 (write-char #\| stream))
548 (defun output-symbol (object stream)
549 (if (or *print-escape* *print-readably*)
550 (let ((package (symbol-package object))
551 (name (symbol-name object)))
553 ;; The ANSI spec "22.1.3.3.1 Package Prefixes for Symbols"
554 ;; requires that keywords be printed with preceding colons
555 ;; always, regardless of the value of *PACKAGE*.
556 ((eq package *keyword-package*)
557 (write-char #\: stream))
558 ;; Otherwise, if the symbol's home package is the current
559 ;; one, then a prefix is never necessary.
560 ((eq package (sane-package)))
561 ;; Uninterned symbols print with a leading #:.
563 (when (or *print-gensym* *print-readably*)
564 (write-string "#:" stream)))
566 (multiple-value-bind (symbol accessible)
567 (find-symbol name (sane-package))
568 ;; If we can find the symbol by looking it up, it need not
569 ;; be qualified. This can happen if the symbol has been
570 ;; inherited from a package other than its home package.
571 (unless (and accessible (eq symbol object))
572 (output-symbol-name (package-name package) stream)
573 (multiple-value-bind (symbol externalp)
574 (find-external-symbol name package)
575 (declare (ignore symbol))
577 (write-char #\: stream)
578 (write-string "::" stream)))))))
579 (output-symbol-name name stream))
580 (output-symbol-name (symbol-name object) stream nil)))
582 ;;; Output the string NAME as if it were a symbol name. In other
583 ;;; words, diddle its case according to *PRINT-CASE* and
585 (defun output-symbol-name (name stream &optional (maybe-quote t))
586 (declare (type simple-base-string name))
587 (setup-printer-state)
588 (if (and maybe-quote (symbol-quotep name))
589 (output-quoted-symbol-name name stream)
590 (funcall *internal-symbol-output-function* name stream)))
592 ;;;; escaping symbols
594 ;;; When we print symbols we have to figure out if they need to be
595 ;;; printed with escape characters. This isn't a whole lot easier than
596 ;;; reading symbols in the first place.
598 ;;; For each character, the value of the corresponding element is a
599 ;;; fixnum with bits set corresponding to attributes that the
600 ;;; character has. At characters have at least one bit set, so we can
601 ;;; search for any character with a positive test.
602 (defvar *character-attributes*
603 (make-array char-code-limit
604 :element-type '(unsigned-byte 16)
606 (declaim (type (simple-array (unsigned-byte 16) (#.char-code-limit))
607 *character-attributes*))
609 ;;; constants which are a bit-mask for each interesting character attribute
610 (defconstant other-attribute (ash 1 0)) ; Anything else legal.
611 (defconstant number-attribute (ash 1 1)) ; A numeric digit.
612 (defconstant uppercase-attribute (ash 1 2)) ; An uppercase letter.
613 (defconstant lowercase-attribute (ash 1 3)) ; A lowercase letter.
614 (defconstant sign-attribute (ash 1 4)) ; +-
615 (defconstant extension-attribute (ash 1 5)) ; ^_
616 (defconstant dot-attribute (ash 1 6)) ; .
617 (defconstant slash-attribute (ash 1 7)) ; /
618 (defconstant funny-attribute (ash 1 8)) ; Anything illegal.
620 (eval-when (:compile-toplevel :load-toplevel :execute)
622 ;;; LETTER-ATTRIBUTE is a local of SYMBOL-QUOTEP. It matches letters
623 ;;; that don't need to be escaped (according to READTABLE-CASE.)
624 (defparameter *attribute-names*
625 `((number . number-attribute) (lowercase . lowercase-attribute)
626 (uppercase . uppercase-attribute) (letter . letter-attribute)
627 (sign . sign-attribute) (extension . extension-attribute)
628 (dot . dot-attribute) (slash . slash-attribute)
629 (other . other-attribute) (funny . funny-attribute)))
633 (flet ((set-bit (char bit)
634 (let ((code (char-code char)))
635 (setf (aref *character-attributes* code)
636 (logior bit (aref *character-attributes* code))))))
638 (dolist (char '(#\! #\@ #\$ #\% #\& #\* #\= #\~ #\[ #\] #\{ #\}
640 (set-bit char other-attribute))
643 (set-bit (digit-char i) number-attribute))
645 (do ((code (char-code #\A) (1+ code))
646 (end (char-code #\Z)))
648 (declare (fixnum code end))
649 (set-bit (code-char code) uppercase-attribute)
650 (set-bit (char-downcase (code-char code)) lowercase-attribute))
652 (set-bit #\- sign-attribute)
653 (set-bit #\+ sign-attribute)
654 (set-bit #\^ extension-attribute)
655 (set-bit #\_ extension-attribute)
656 (set-bit #\. dot-attribute)
657 (set-bit #\/ slash-attribute)
659 ;; Mark anything not explicitly allowed as funny.
660 (dotimes (i char-code-limit)
661 (when (zerop (aref *character-attributes* i))
662 (setf (aref *character-attributes* i) funny-attribute))))
664 ;;; For each character, the value of the corresponding element is the
665 ;;; lowest base in which that character is a digit.
666 (defvar *digit-bases*
667 (make-array char-code-limit
668 :element-type '(unsigned-byte 8)
669 :initial-element 36))
670 (declaim (type (simple-array (unsigned-byte 8) (#.char-code-limit))
674 (let ((char (digit-char i 36)))
675 (setf (aref *digit-bases* (char-code char)) i)))
677 ;;; A FSM-like thingie that determines whether a symbol is a potential
678 ;;; number or has evil characters in it.
679 (defun symbol-quotep (name)
680 (declare (simple-string name))
681 (macrolet ((advance (tag &optional (at-end t))
684 ,(if at-end '(go TEST-SIGN) '(return nil)))
685 (setq current (schar name index)
686 code (char-code current)
687 bits (aref attributes code))
690 (test (&rest attributes)
702 `(< (the fixnum (aref bases code)) base)))
704 (prog ((len (length name))
705 (attributes *character-attributes*)
706 (bases *digit-bases*)
709 (case (readtable-case *readtable*)
710 (:upcase uppercase-attribute)
711 (:downcase lowercase-attribute)
712 (t (logior lowercase-attribute uppercase-attribute))))
717 (declare (fixnum len base index bits code))
720 TEST-SIGN ; At end, see whether it is a sign...
721 (return (not (test sign)))
723 OTHER ; not potential number, see whether funny chars...
724 (let ((mask (logxor (logior lowercase-attribute uppercase-attribute
727 (do ((i (1- index) (1+ i)))
728 ((= i len) (return-from symbol-quotep nil))
729 (unless (zerop (logand (aref attributes (char-code (schar name i)))
731 (return-from symbol-quotep t))))
736 (advance LAST-DIGIT-ALPHA)
738 (when (test letter number other slash) (advance OTHER nil))
739 (when (char= current #\.) (advance DOT-FOUND))
740 (when (test sign extension) (advance START-STUFF nil))
743 DOT-FOUND ; leading dots...
744 (when (test letter) (advance START-DOT-MARKER nil))
745 (when (digitp) (advance DOT-DIGIT))
746 (when (test number other) (advance OTHER nil))
747 (when (test extension slash sign) (advance START-DOT-STUFF nil))
748 (when (char= current #\.) (advance DOT-FOUND))
751 START-STUFF ; leading stuff before any dot or digit
754 (advance LAST-DIGIT-ALPHA)
756 (when (test number other) (advance OTHER nil))
757 (when (test letter) (advance START-MARKER nil))
758 (when (char= current #\.) (advance START-DOT-STUFF nil))
759 (when (test sign extension slash) (advance START-STUFF nil))
762 START-MARKER ; number marker in leading stuff...
763 (when (test letter) (advance OTHER nil))
766 START-DOT-STUFF ; leading stuff containing dot without digit...
767 (when (test letter) (advance START-DOT-STUFF nil))
768 (when (digitp) (advance DOT-DIGIT))
769 (when (test sign extension dot slash) (advance START-DOT-STUFF nil))
770 (when (test number other) (advance OTHER nil))
773 START-DOT-MARKER ; number marker in leading stuff with dot..
774 ;; leading stuff containing dot without digit followed by letter...
775 (when (test letter) (advance OTHER nil))
778 DOT-DIGIT ; in a thing with dots...
779 (when (test letter) (advance DOT-MARKER))
780 (when (digitp) (advance DOT-DIGIT))
781 (when (test number other) (advance OTHER nil))
782 (when (test sign extension dot slash) (advance DOT-DIGIT))
785 DOT-MARKER ; number marker in number with dot...
786 (when (test letter) (advance OTHER nil))
789 LAST-DIGIT-ALPHA ; previous char is a letter digit...
790 (when (or (digitp) (test sign slash))
791 (advance ALPHA-DIGIT))
792 (when (test letter number other dot) (advance OTHER nil))
795 ALPHA-DIGIT ; seen a digit which is a letter...
796 (when (or (digitp) (test sign slash))
798 (advance LAST-DIGIT-ALPHA)
799 (advance ALPHA-DIGIT)))
800 (when (test letter) (advance ALPHA-MARKER))
801 (when (test number other dot) (advance OTHER nil))
804 ALPHA-MARKER ; number marker in number with alpha digit...
805 (when (test letter) (advance OTHER nil))
808 DIGIT ; seen only ordinary (non-alphabetic) numeric digits...
811 (advance ALPHA-DIGIT)
813 (when (test number other) (advance OTHER nil))
814 (when (test letter) (advance MARKER))
815 (when (test extension slash sign) (advance DIGIT))
816 (when (char= current #\.) (advance DOT-DIGIT))
819 MARKER ; number marker in a numeric number...
820 (when (test letter) (advance OTHER nil))
823 ;;;; *INTERNAL-SYMBOL-OUTPUT-FUNCTION*
825 ;;;; Case hackery. These functions are stored in
826 ;;;; *INTERNAL-SYMBOL-OUTPUT-FUNCTION* according to the values of
827 ;;;; *PRINT-CASE* and READTABLE-CASE.
830 ;;; READTABLE-CASE *PRINT-CASE*
832 ;;; :DOWNCASE :DOWNCASE
834 (defun output-preserve-symbol (pname stream)
835 (declare (simple-string pname))
836 (write-string pname stream))
839 ;;; READTABLE-CASE *PRINT-CASE*
840 ;;; :UPCASE :DOWNCASE
841 (defun output-lowercase-symbol (pname stream)
842 (declare (simple-string pname))
843 (dotimes (index (length pname))
844 (let ((char (schar pname index)))
845 (write-char (char-downcase char) stream))))
848 ;;; READTABLE-CASE *PRINT-CASE*
849 ;;; :DOWNCASE :UPCASE
850 (defun output-uppercase-symbol (pname stream)
851 (declare (simple-string pname))
852 (dotimes (index (length pname))
853 (let ((char (schar pname index)))
854 (write-char (char-upcase char) stream))))
857 ;;; READTABLE-CASE *PRINT-CASE*
858 ;;; :UPCASE :CAPITALIZE
859 ;;; :DOWNCASE :CAPITALIZE
860 (defun output-capitalize-symbol (pname stream)
861 (declare (simple-string pname))
862 (let ((prev-not-alpha t)
863 (up (eq (readtable-case *readtable*) :upcase)))
864 (dotimes (i (length pname))
865 (let ((char (char pname i)))
867 (if (or prev-not-alpha (lower-case-p char))
869 (char-downcase char))
874 (setq prev-not-alpha (not (alpha-char-p char)))))))
877 ;;; READTABLE-CASE *PRINT-CASE*
879 (defun output-invert-symbol (pname stream)
880 (declare (simple-string pname))
883 (dotimes (i (length pname))
884 (let ((ch (schar pname i)))
885 (when (both-case-p ch)
886 (if (upper-case-p ch)
888 (setq all-upper nil)))))
889 (cond (all-upper (output-lowercase-symbol pname stream))
890 (all-lower (output-uppercase-symbol pname stream))
892 (write-string pname stream)))))
896 (let ((*readtable* (copy-readtable nil)))
897 (format t "READTABLE-CASE Input Symbol-name~@
898 ----------------------------------~%")
899 (dolist (readtable-case '(:upcase :downcase :preserve :invert))
900 (setf (readtable-case *readtable*) readtable-case)
901 (dolist (input '("ZEBRA" "Zebra" "zebra"))
902 (format t "~&:~A~16T~A~24T~A"
903 (string-upcase readtable-case)
905 (symbol-name (read-from-string input)))))))
908 (let ((*readtable* (copy-readtable nil)))
909 (format t "READTABLE-CASE *PRINT-CASE* Symbol-name Output Princ~@
910 --------------------------------------------------------~%")
911 (dolist (readtable-case '(:upcase :downcase :preserve :invert))
912 (setf (readtable-case *readtable*) readtable-case)
913 (dolist (*print-case* '(:upcase :downcase :capitalize))
914 (dolist (symbol '(|ZEBRA| |Zebra| |zebra|))
915 (format t "~&:~A~15T:~A~29T~A~42T~A~50T~A"
916 (string-upcase readtable-case)
917 (string-upcase *print-case*)
919 (prin1-to-string symbol)
920 (princ-to-string symbol)))))))
923 ;;;; recursive objects
925 (defun output-list (list stream)
926 (descend-into (stream)
927 (write-char #\( stream)
931 (punt-print-if-too-long length stream)
932 (output-object (pop list) stream)
935 (when (or (atom list) (check-for-circularity list))
936 (write-string " . " stream)
937 (output-object list stream)
939 (write-char #\space stream)
941 (write-char #\) stream)))
943 (defun output-vector (vector stream)
944 (declare (vector vector))
945 (cond ((stringp vector)
946 (cond ((or *print-escape* *print-readably*)
947 (write-char #\" stream)
948 (quote-string vector stream)
949 (write-char #\" stream))
951 (write-string vector stream))))
952 ((not (or *print-array* *print-readably*))
953 (output-terse-array vector stream))
954 ((bit-vector-p vector)
955 (write-string "#*" stream)
956 (dovector (bit vector)
957 ;; (Don't use OUTPUT-OBJECT here, since this code
958 ;; has to work for all possible *PRINT-BASE* values.)
959 (write-char (if (zerop bit) #\0 #\1) stream)))
961 (when (and *print-readably*
962 (not (eq (array-element-type vector) t)))
963 (error 'print-not-readable :object vector))
964 (descend-into (stream)
965 (write-string "#(" stream)
966 (dotimes (i (length vector))
968 (write-char #\space stream))
969 (punt-print-if-too-long i stream)
970 (output-object (aref vector i) stream))
971 (write-string ")" stream)))))
973 ;;; This function outputs a string quoting characters sufficiently
974 ;;; so that someone can read it in again. Basically, put a slash in
975 ;;; front of an character satisfying NEEDS-SLASH-P.
976 (defun quote-string (string stream)
977 (macrolet ((needs-slash-p (char)
978 ;; KLUDGE: We probably should look at the readtable, but just do
979 ;; this for now. [noted by anonymous long ago] -- WHN 19991130
980 `(or (char= ,char #\\)
982 (with-array-data ((data string) (start) (end (length string)))
983 (do ((index start (1+ index)))
985 (let ((char (schar data index)))
986 (when (needs-slash-p char) (write-char #\\ stream))
987 (write-char char stream))))))
989 ;;; Output the printed representation of any array in either the #< or #A
991 (defun output-array (array stream)
992 (if (or *print-array* *print-readably*)
993 (output-array-guts array stream)
994 (output-terse-array array stream)))
996 ;;; Output the abbreviated #< form of an array.
997 (defun output-terse-array (array stream)
998 (let ((*print-level* nil)
999 (*print-length* nil))
1000 (print-unreadable-object (array stream :type t :identity t))))
1002 ;;; Output the readable #A form of an array.
1003 (defun output-array-guts (array stream)
1004 (when (and *print-readably*
1005 (not (eq (array-element-type array) t)))
1006 (error 'print-not-readable :object array))
1007 (write-char #\# stream)
1008 (let ((*print-base* 10))
1009 (output-integer (array-rank array) stream))
1010 (write-char #\A stream)
1011 (with-array-data ((data array) (start) (end))
1012 (declare (ignore end))
1013 (sub-output-array-guts data (array-dimensions array) stream start)))
1015 (defun sub-output-array-guts (array dimensions stream index)
1016 (declare (type (simple-array * (*)) array) (fixnum index))
1017 (cond ((null dimensions)
1018 (output-object (aref array index) stream))
1020 (descend-into (stream)
1021 (write-char #\( stream)
1022 (let* ((dimension (car dimensions))
1023 (dimensions (cdr dimensions))
1024 (count (reduce #'* dimensions)))
1025 (dotimes (i dimension)
1027 (write-char #\space stream))
1028 (punt-print-if-too-long i stream)
1029 (sub-output-array-guts array dimensions stream index)
1030 (incf index count)))
1031 (write-char #\) stream)))))
1033 ;;; a trivial non-generic-function placeholder for PRINT-OBJECT, for
1034 ;;; use until CLOS is set up (at which time it will be replaced with
1035 ;;; the real generic function implementation)
1036 (defun print-object (instance stream)
1037 (default-structure-print instance stream *current-level*))
1039 ;;;; integer, ratio, and complex printing (i.e. everything but floats)
1041 (defun output-integer (integer stream)
1042 ;; FIXME: This UNLESS form should be pulled out into something like
1043 ;; (SANE-PRINT-BASE), along the lines of (SANE-PACKAGE) for the
1044 ;; *PACKAGE* variable.
1045 (unless (and (fixnump *print-base*)
1046 (< 1 *print-base* 37))
1047 (let ((obase *print-base*))
1048 (setq *print-base* 10.)
1049 (error "~A is not a reasonable value for *PRINT-BASE*." obase)))
1050 (when (and (not (= *print-base* 10.))
1052 ;; First print leading base information, if any.
1053 (write-char #\# stream)
1054 (write-char (case *print-base*
1058 (T (let ((fixbase *print-base*)
1061 (sub-output-integer fixbase stream))
1064 ;; Then output a minus sign if the number is negative, then output
1065 ;; the absolute value of the number.
1066 (cond ((bignump integer) (print-bignum integer stream))
1068 (write-char #\- stream)
1069 (sub-output-integer (- integer) stream))
1071 (sub-output-integer integer stream)))
1072 ;; Print any trailing base information, if any.
1073 (if (and (= *print-base* 10.) *print-radix*)
1074 (write-char #\. stream)))
1076 (defun sub-output-integer (integer stream)
1079 ;; Recurse until you have all the digits pushed on the stack.
1080 (if (not (zerop (multiple-value-setq (quotient remainder)
1081 (truncate integer *print-base*))))
1082 (sub-output-integer quotient stream))
1083 ;; Then as each recursive call unwinds, turn the digit (in remainder)
1084 ;; into a character and output the character.
1085 (write-char (code-char (if (and (> remainder 9.)
1086 (> *print-base* 10.))
1087 (+ (char-code #\A) (- remainder 10.))
1088 (+ (char-code #\0) remainder)))
1091 ;;;; bignum printing
1093 ;;; *BASE-POWER* holds the number that we keep dividing into the
1094 ;;; bignum for each *print-base*. We want this number as close to
1095 ;;; *most-positive-fixnum* as possible, i.e. (floor (log
1096 ;;; most-positive-fixnum *print-base*)).
1097 (defparameter *base-power* (make-array 37 :initial-element nil))
1099 ;;; *FIXNUM-POWER--1* holds the number of digits for each *PRINT-BASE*
1100 ;;; that fit in the corresponding *base-power*.
1101 (defparameter *fixnum-power--1* (make-array 37 :initial-element nil))
1103 ;;; Print the bignum to the stream. We first generate the correct
1104 ;;; value for *base-power* and *fixnum-power--1* if we have not
1105 ;;; already. Then we call bignum-print-aux to do the printing.
1106 (defun print-bignum (big stream)
1107 (unless (aref *base-power* *print-base*)
1108 (do ((power-1 -1 (1+ power-1))
1109 (new-divisor *print-base* (* new-divisor *print-base*))
1110 (divisor 1 new-divisor))
1111 ((not (fixnump new-divisor))
1112 (setf (aref *base-power* *print-base*) divisor)
1113 (setf (aref *fixnum-power--1* *print-base*) power-1))))
1114 (bignum-print-aux (cond ((minusp big)
1115 (write-char #\- stream)
1118 (aref *base-power* *print-base*)
1119 (aref *fixnum-power--1* *print-base*)
1123 (defun bignum-print-aux (big divisor power-1 stream)
1124 (multiple-value-bind (newbig fix) (truncate big divisor)
1125 (if (fixnump newbig)
1126 (sub-output-integer newbig stream)
1127 (bignum-print-aux newbig divisor power-1 stream))
1128 (do ((zeros power-1 (1- zeros))
1129 (base-power *print-base* (* base-power *print-base*)))
1131 (dotimes (i zeros) (write-char #\0 stream))
1132 (sub-output-integer fix stream)))))
1134 (defun output-ratio (ratio stream)
1136 (write-char #\# stream)
1138 (2 (write-char #\b stream))
1139 (8 (write-char #\o stream))
1140 (16 (write-char #\x stream))
1141 (t (write *print-base* :stream stream :radix nil :base 10)))
1142 (write-char #\r stream))
1143 (let ((*print-radix* nil))
1144 (output-integer (numerator ratio) stream)
1145 (write-char #\/ stream)
1146 (output-integer (denominator ratio) stream)))
1148 (defun output-complex (complex stream)
1149 (write-string "#C(" stream)
1150 (output-object (realpart complex) stream)
1151 (write-char #\space stream)
1152 (output-object (imagpart complex) stream)
1153 (write-char #\) stream))
1157 ;;; FLONUM-TO-STRING (and its subsidiary function FLOAT-STRING) does
1158 ;;; most of the work for all printing of floating point numbers in the
1159 ;;; printer and in FORMAT. It converts a floating point number to a
1160 ;;; string in a free or fixed format with no exponent. The
1161 ;;; interpretation of the arguments is as follows:
1163 ;;; X - The floating point number to convert, which must not be
1165 ;;; WIDTH - The preferred field width, used to determine the number
1166 ;;; of fraction digits to produce if the FDIGITS parameter
1167 ;;; is unspecified or NIL. If the non-fraction digits and the
1168 ;;; decimal point alone exceed this width, no fraction digits
1169 ;;; will be produced unless a non-NIL value of FDIGITS has been
1170 ;;; specified. Field overflow is not considerd an error at this
1172 ;;; FDIGITS - The number of fractional digits to produce. Insignificant
1173 ;;; trailing zeroes may be introduced as needed. May be
1174 ;;; unspecified or NIL, in which case as many digits as possible
1175 ;;; are generated, subject to the constraint that there are no
1176 ;;; trailing zeroes.
1177 ;;; SCALE - If this parameter is specified or non-NIL, then the number
1178 ;;; printed is (* x (expt 10 scale)). This scaling is exact,
1179 ;;; and cannot lose precision.
1180 ;;; FMIN - This parameter, if specified or non-NIL, is the minimum
1181 ;;; number of fraction digits which will be produced, regardless
1182 ;;; of the value of WIDTH or FDIGITS. This feature is used by
1183 ;;; the ~E format directive to prevent complete loss of
1184 ;;; significance in the printed value due to a bogus choice of
1187 ;;; Most of the optional arguments are for the benefit for FORMAT and are not
1188 ;;; used by the printer.
1191 ;;; (VALUES DIGIT-STRING DIGIT-LENGTH LEADING-POINT TRAILING-POINT DECPNT)
1192 ;;; where the results have the following interpretation:
1194 ;;; DIGIT-STRING - The decimal representation of X, with decimal point.
1195 ;;; DIGIT-LENGTH - The length of the string DIGIT-STRING.
1196 ;;; LEADING-POINT - True if the first character of DIGIT-STRING is the
1198 ;;; TRAILING-POINT - True if the last character of DIGIT-STRING is the
1200 ;;; POINT-POS - The position of the digit preceding the decimal
1201 ;;; point. Zero indicates point before first digit.
1203 ;;; NOTE: FLONUM-TO-STRING goes to a lot of trouble to guarantee
1204 ;;; accuracy. Specifically, the decimal number printed is the closest
1205 ;;; possible approximation to the true value of the binary number to
1206 ;;; be printed from among all decimal representations with the same
1207 ;;; number of digits. In free-format output, i.e. with the number of
1208 ;;; digits unconstrained, it is guaranteed that all the information is
1209 ;;; preserved, so that a properly- rounding reader can reconstruct the
1210 ;;; original binary number, bit-for-bit, from its printed decimal
1211 ;;; representation. Furthermore, only as many digits as necessary to
1212 ;;; satisfy this condition will be printed.
1214 ;;; FLOAT-STRING actually generates the digits for positive numbers.
1215 ;;; The algorithm is essentially that of algorithm Dragon4 in "How to
1216 ;;; Print Floating-Point Numbers Accurately" by Steele and White. The
1217 ;;; current (draft) version of this paper may be found in
1218 ;;; [CMUC]<steele>tradix.press. DO NOT EVEN THINK OF ATTEMPTING TO
1219 ;;; UNDERSTAND THIS CODE WITHOUT READING THE PAPER!
1221 (defvar *digits* "0123456789")
1223 (defun flonum-to-string (x &optional width fdigits scale fmin)
1225 ;; Zero is a special case which FLOAT-STRING cannot handle.
1227 (let ((s (make-string (1+ fdigits) :initial-element #\0)))
1228 (setf (schar s 0) #\.)
1229 (values s (length s) t (zerop fdigits) 0))
1230 (values "." 1 t t 0)))
1232 (multiple-value-bind (sig exp) (integer-decode-float x)
1233 (let* ((precision (float-precision x))
1234 (digits (float-digits x))
1235 (fudge (- digits precision))
1236 (width (if width (max width 1) nil)))
1237 (float-string (ash sig (- fudge)) (+ exp fudge) precision width
1238 fdigits scale fmin))))))
1240 (defun float-string (fraction exponent precision width fdigits scale fmin)
1241 (let ((r fraction) (s 1) (m- 1) (m+ 1) (k 0)
1242 (digits 0) (decpnt 0) (cutoff nil) (roundup nil) u low high
1243 (digit-string (make-array 50
1244 :element-type 'base-char
1247 ;; Represent fraction as r/s, error bounds as m+/s and m-/s.
1248 ;; Rational arithmetic avoids loss of precision in subsequent
1250 (cond ((> exponent 0)
1251 (setq r (ash fraction exponent))
1252 (setq m- (ash 1 exponent))
1255 (setq s (ash 1 (- exponent)))))
1256 ;; Adjust the error bounds m+ and m- for unequal gaps.
1257 (when (= fraction (ash 1 precision))
1258 (setq m+ (ash m+ 1))
1261 ;; Scale value by requested amount, and update error bounds.
1264 (let ((scale-factor (expt 10 (- scale))))
1265 (setq s (* s scale-factor)))
1266 (let ((scale-factor (expt 10 scale)))
1267 (setq r (* r scale-factor))
1268 (setq m+ (* m+ scale-factor))
1269 (setq m- (* m- scale-factor)))))
1270 ;; Scale r and s and compute initial k, the base 10 logarithm of r.
1272 ((>= r (ceiling s 10)))
1276 (setq m+ (* m+ 10)))
1279 ((< (+ (ash r 1) m+) (ash s 1)))
1282 ;; Determine number of fraction digits to generate.
1284 ;; Use specified number of fraction digits.
1285 (setq cutoff (- fdigits))
1286 ;;don't allow less than fmin fraction digits
1287 (if (and fmin (> cutoff (- fmin))) (setq cutoff (- fmin))))
1289 ;; Use as many fraction digits as width will permit but
1290 ;; force at least fmin digits even if width will be
1293 (setq cutoff (- 1 width))
1294 (setq cutoff (1+ (- k width))))
1295 (if (and fmin (> cutoff (- fmin))) (setq cutoff (- fmin)))))
1296 ;; If we decided to cut off digit generation before precision
1297 ;; has been exhausted, rounding the last digit may cause a carry
1298 ;; propagation. We can prevent this, preserving left-to-right
1299 ;; digit generation, with a few magical adjustments to m- and
1300 ;; m+. Of course, correct rounding is also preserved.
1301 (when (or fdigits width)
1302 (let ((a (- cutoff k))
1305 (dotimes (i a) (setq y (* y 10)))
1306 (dotimes (i (- a)) (setq y (ceiling y 10))))
1307 (setq m- (max y m-))
1308 (setq m+ (max y m+))
1309 (when (= m+ y) (setq roundup t))))
1310 (when (< (+ (ash r 1) m+) (ash s 1)) (return)))
1311 ;; Zero-fill before fraction if no integer part.
1313 (setq decpnt digits)
1314 (vector-push-extend #\. digit-string)
1316 (incf digits) (vector-push-extend #\0 digit-string)))
1317 ;; Generate the significant digits.
1321 (vector-push-extend #\. digit-string)
1322 (setq decpnt digits))
1323 (multiple-value-setq (u r) (truncate (* r 10) s))
1326 (setq low (< (ash r 1) m-))
1328 (setq high (>= (ash r 1) (- (ash s 1) m+)))
1329 (setq high (> (ash r 1) (- (ash s 1) m+))))
1330 ;; Stop when either precision is exhausted or we have printed as
1331 ;; many fraction digits as permitted.
1332 (when (or low high (and cutoff (<= k cutoff))) (return))
1333 (vector-push-extend (char *digits* u) digit-string)
1335 ;; If cutoff occurred before first digit, then no digits are
1336 ;; generated at all.
1337 (when (or (not cutoff) (>= k cutoff))
1338 ;; Last digit may need rounding
1339 (vector-push-extend (char *digits*
1340 (cond ((and low (not high)) u)
1341 ((and high (not low)) (1+ u))
1342 (t (if (<= (ash r 1) s) u (1+ u)))))
1345 ;; Zero-fill after integer part if no fraction.
1347 (dotimes (i k) (incf digits) (vector-push-extend #\0 digit-string))
1348 (vector-push-extend #\. digit-string)
1349 (setq decpnt digits))
1350 ;; Add trailing zeroes to pad fraction if fdigits specified.
1352 (dotimes (i (- fdigits (- digits decpnt)))
1354 (vector-push-extend #\0 digit-string)))
1356 (values digit-string (1+ digits) (= decpnt 0) (= decpnt digits) decpnt)))
1358 ;;; Given a non-negative floating point number, SCALE-EXPONENT returns
1359 ;;; a new floating point number Z in the range (0.1, 1.0] and an
1360 ;;; exponent E such that Z * 10^E is (approximately) equal to the
1361 ;;; original number. There may be some loss of precision due the
1362 ;;; floating point representation. The scaling is always done with
1363 ;;; long float arithmetic, which helps printing of lesser precisions
1364 ;;; as well as avoiding generic arithmetic.
1366 ;;; When computing our initial scale factor using EXPT, we pull out
1367 ;;; part of the computation to avoid over/under flow. When
1368 ;;; denormalized, we must pull out a large factor, since there is more
1369 ;;; negative exponent range than positive range.
1370 (defun scale-exponent (original-x)
1371 (let* ((x (coerce original-x 'long-float)))
1372 (multiple-value-bind (sig exponent) (decode-float x)
1373 (declare (ignore sig))
1375 (values (float 0.0l0 original-x) 1)
1376 (let* ((ex (round (* exponent (log 2l0 10))))
1378 (if (float-denormalized-p x)
1380 (* x 1.0l16 (expt 10.0l0 (- (- ex) 16)))
1382 (* x 1.0l18 (expt 10.0l0 (- (- ex) 18)))
1383 (* x 10.0l0 (expt 10.0l0 (- (- ex) 1))))
1384 (/ x 10.0l0 (expt 10.0l0 (1- ex))))))
1385 (do ((d 10.0l0 (* d 10.0l0))
1389 (do ((m 10.0l0 (* m 10.0l0))
1393 (values (float z original-x) ex))))))))))
1395 ;;;; entry point for the float printer
1397 ;;; the float printer as called by PRINT, PRIN1, PRINC, etc. The
1398 ;;; argument is printed free-format, in either exponential or
1399 ;;; non-exponential notation, depending on its magnitude.
1401 ;;; NOTE: When a number is to be printed in exponential format, it is
1402 ;;; scaled in floating point. Since precision may be lost in this
1403 ;;; process, the guaranteed accuracy properties of FLONUM-TO-STRING
1404 ;;; are lost. The difficulty is that FLONUM-TO-STRING performs
1405 ;;; extensive computations with integers of similar magnitude to that
1406 ;;; of the number being printed. For large exponents, the bignums
1407 ;;; really get out of hand. If bignum arithmetic becomes reasonably
1408 ;;; fast and the exponent range is not too large, then it might become
1409 ;;; attractive to handle exponential notation with the same accuracy
1410 ;;; as non-exponential notation, using the method described in the
1411 ;;; Steele and White paper.
1413 ;;; Print the appropriate exponent marker for X and the specified exponent.
1414 (defun print-float-exponent (x exp stream)
1415 (declare (type float x) (type integer exp) (type stream stream))
1416 (let ((*print-radix* nil)
1417 (plusp (plusp exp)))
1418 (if (typep x *read-default-float-format*)
1420 (format stream "e~:[~;+~]~D" plusp exp))
1421 (format stream "~C~:[~;+~]~D"
1429 (defun output-float-infinity (x stream)
1430 (declare (float x) (stream stream))
1432 (write-string "#." stream))
1434 (error 'print-not-readable :object x))
1436 (write-string "#<" stream)))
1437 (write-string "SB-EXT:" stream)
1438 (write-string (symbol-name (float-format-name x)) stream)
1439 (write-string (if (plusp x) "-POSITIVE-" "-NEGATIVE-")
1441 (write-string "INFINITY" stream)
1443 (write-string ">" stream)))
1445 (defun output-float-nan (x stream)
1446 (print-unreadable-object (x stream)
1447 (princ (float-format-name x) stream)
1448 (write-string (if (float-trapping-nan-p x) " trapping" " quiet") stream)
1449 (write-string " NaN" stream)))
1451 ;;; the function called by OUTPUT-OBJECT to handle floats
1452 (defun output-float (x stream)
1454 ((float-infinity-p x)
1455 (output-float-infinity x stream))
1457 (output-float-nan x stream))
1459 (let ((x (cond ((minusp (float-sign x))
1460 (write-char #\- stream)
1466 (write-string "0.0" stream)
1467 (print-float-exponent x 0 stream))
1469 (output-float-aux x stream (float 1/1000 x) (float 10000000 x))))))))
1470 (defun output-float-aux (x stream e-min e-max)
1471 (if (and (>= x e-min) (< x e-max))
1473 (multiple-value-bind (str len lpoint tpoint) (flonum-to-string x)
1474 (declare (ignore len))
1475 (when lpoint (write-char #\0 stream))
1476 (write-string str stream)
1477 (when tpoint (write-char #\0 stream))
1478 (print-float-exponent x 0 stream))
1479 ;; exponential format
1480 (multiple-value-bind (f ex) (scale-exponent x)
1481 (multiple-value-bind (str len lpoint tpoint)
1482 (flonum-to-string f nil nil 1)
1483 (declare (ignore len))
1484 (when lpoint (write-char #\0 stream))
1485 (write-string str stream)
1486 (when tpoint (write-char #\0 stream))
1487 ;; Subtract out scale factor of 1 passed to FLONUM-TO-STRING.
1488 (print-float-exponent x (1- ex) stream)))))
1490 ;;;; other leaf objects
1492 ;;; If *PRINT-ESCAPE* is false, just do a WRITE-CHAR, otherwise output
1493 ;;; the character name or the character in the #\char format.
1494 (defun output-character (char stream)
1495 (if (or *print-escape* *print-readably*)
1496 (let ((name (char-name char)))
1497 (write-string "#\\" stream)
1499 (quote-string name stream)
1500 (write-char char stream)))
1501 (write-char char stream)))
1503 (defun output-sap (sap stream)
1504 (declare (type system-area-pointer sap))
1506 (format stream "#.(~S #X~8,'0X)" 'int-sap (sap-int sap)))
1508 (print-unreadable-object (sap stream)
1509 (format stream "system area pointer: #X~8,'0X" (sap-int sap))))))
1511 (defun output-weak-pointer (weak-pointer stream)
1512 (declare (type weak-pointer weak-pointer))
1513 (print-unreadable-object (weak-pointer stream)
1514 (multiple-value-bind (value validp) (weak-pointer-value weak-pointer)
1516 (write-string "weak pointer: " stream)
1517 (write value :stream stream))
1519 (write-string "broken weak pointer" stream))))))
1521 (defun output-code-component (component stream)
1522 (print-unreadable-object (component stream :identity t)
1523 (let ((dinfo (%code-debug-info component)))
1524 (cond ((eq dinfo :bogus-lra)
1525 (write-string "bogus code object" stream))
1527 (write-string "code object" stream)
1529 (write-char #\space stream)
1530 (output-object (sb!c::debug-info-name dinfo) stream)))))))
1532 (defun output-lra (lra stream)
1533 (print-unreadable-object (lra stream :identity t)
1534 (write-string "return PC object" stream)))
1536 (defun output-fdefn (fdefn stream)
1537 (print-unreadable-object (fdefn stream)
1538 (write-string "FDEFINITION object for " stream)
1539 (output-object (fdefn-name fdefn) stream)))
1543 ;;; Output OBJECT as using PRINT-OBJECT if it's a
1544 ;;; FUNCALLABLE-STANDARD-CLASS, or return NIL otherwise.
1546 ;;; The definition here is a simple temporary placeholder. It will be
1547 ;;; overwritten by a smarter version (capable of calling generic
1548 ;;; PRINT-OBJECT when appropriate) when CLOS is installed.
1549 (defun printed-as-clos-funcallable-standard-class (object stream)
1550 (declare (ignore object stream))
1553 (defun output-function (object stream)
1554 (let* ((*print-length* 3) ; in case we have to..
1555 (*print-level* 3) ; ..print an interpreted function definition
1556 (name (cond ((find (function-subtype object)
1557 #(#.sb!vm:closure-header-type
1558 #.sb!vm:byte-code-closure-type))
1560 ((sb!eval::interpreted-function-p object)
1561 (or (sb!eval::interpreted-function-%name object)
1562 (sb!eval:interpreted-function-lambda-expression
1564 ((find (function-subtype object)
1565 #(#.sb!vm:function-header-type
1566 #.sb!vm:closure-function-header-type))
1567 (%function-name object))
1568 (t 'no-name-available)))
1569 (identified-by-name-p (and (symbolp name)
1571 (eq (fdefinition name) object))))
1572 (print-unreadable-object (object
1574 :identity (not identified-by-name-p))
1575 (prin1 'function stream)
1576 (unless (eq name 'no-name-available)
1577 (format stream " ~S" name)))))
1579 ;;;; catch-all for unknown things
1581 (defun output-random (object stream)
1582 (print-unreadable-object (object stream :identity t)
1583 (let ((lowtag (get-lowtag object)))
1585 (#.sb!vm:other-pointer-type
1586 (let ((type (get-type object)))
1588 (#.sb!vm:value-cell-header-type
1589 (write-string "value cell " stream)
1590 (output-object (sb!c:value-cell-ref object) stream))
1592 (write-string "unknown pointer object, type=" stream)
1593 (let ((*print-base* 16) (*print-radix* t))
1594 (output-integer type stream))))))
1595 ((#.sb!vm:function-pointer-type
1596 #.sb!vm:instance-pointer-type
1597 #.sb!vm:list-pointer-type)
1598 (write-string "unknown pointer object, type=" stream))
1600 (case (get-type object)
1601 (#.sb!vm:unbound-marker-type
1602 (write-string "unbound marker" stream))
1604 (write-string "unknown immediate object, lowtag=" stream)
1605 (let ((*print-base* 2) (*print-radix* t))
1606 (output-integer lowtag stream))
1607 (write-string ", type=" stream)
1608 (let ((*print-base* 16) (*print-radix* t))
1609 (output-integer (get-type object) stream)))))))))